Guzman is believed to have led the Sinaloa cartel for decades, as it became the largest drug trafficking organization in the world. U.S. prosecutors say he oversaw hundreds of murders, kidnappings and other violent acts.

Guzman slept in a cell Monday night inside the highly-secure federal courthouse in Brooklyn, which is now a virtual fortress. He was brought into court Monday wearing a suit and a shirt with a wide-open collar, but no handcuffs, as he faced the men and women who could ultimately decide his fate, reports CBS News' Nikki Battiste.

From the moment he set foot on U.S. soil, Guzman has seemingly been surrounded by federal agents wherever he goes. Jurors will get a taste of that if they're selected for his trial. U.S. Marshals will escort them to and from the courthouse every day for their own safety.

CBS News legal analyst Rikki Klieman said the names of Guzman's jurors are being kept a secret to foil any hit men and prevent bribes.

"These jurors are going to be protected in a way that is highly unusual," Klieman said. "No one will know their names. They won't know their addresses, their occupations. This will not become information for the public or certainly not for the Sinaloa drug cartel."

On Monday, a potential juror was dismissed after she told the judge, "What scares me is that...[Guzman's] family will come after jurors and their family." Another said: "I'm nervous." Others were asked if they had watched popular Netflix shows about drug trafficking like "El Chapo." A woman who watched "Narcos" was dismissed.

Guzman's lawyers say the increased security measures create an unfair impression he is a violent man. He has pleaded not guilty to 17 counts of drug smuggling and money laundering.

"He's a mythical figure at this point. And if you read the books, the many books that have been written about him, even by the agents in the case, they even discuss it – they don't know what was real and what wasn't real," said Guzman's attorney, Jeffrey Lichtman.

Guzman famously escaped from Mexican prisons twice, once in 2015 by riding a motorcycle through a mile-long tunnel. He was recaptured six months later and then extradited to the U.S. To prevent Guzman from escaping again, Marshals have even shut down parts of the Brooklyn Bridge so he can be moved from his Manhattan cell for all his pretrial hearings.

"No one wants to take the chance that something out of a 'Mission Impossible' movie happens, where suddenly a helicopter comes down and people come out of the water, and the next thing we know is that 'El Chapo' is gone. That is not going to happen during this trial," Klieman said.

Jurors will be partially sequestered for what's expected to be a four-month-long trial. There were also some moments of levity during Monday's jury selection. One man said he was a professional Michael Jackson impersonator and another admitted to eating a sandwich called "El Chapo," which he said was "delicious."